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net/mlx5_core: Print resource number on QP/SRQ async events
[deliverable/linux.git] / drivers / net / xen-netfront.c
1 /*
2 * Virtual network driver for conversing with remote driver backends.
3 *
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
19 *
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 * IN THE SOFTWARE.
30 */
31
32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/netdevice.h>
37 #include <linux/etherdevice.h>
38 #include <linux/skbuff.h>
39 #include <linux/ethtool.h>
40 #include <linux/if_ether.h>
41 #include <net/tcp.h>
42 #include <linux/udp.h>
43 #include <linux/moduleparam.h>
44 #include <linux/mm.h>
45 #include <linux/slab.h>
46 #include <net/ip.h>
47
48 #include <asm/xen/page.h>
49 #include <xen/xen.h>
50 #include <xen/xenbus.h>
51 #include <xen/events.h>
52 #include <xen/page.h>
53 #include <xen/platform_pci.h>
54 #include <xen/grant_table.h>
55
56 #include <xen/interface/io/netif.h>
57 #include <xen/interface/memory.h>
58 #include <xen/interface/grant_table.h>
59
60 /* Module parameters */
61 static unsigned int xennet_max_queues;
62 module_param_named(max_queues, xennet_max_queues, uint, 0644);
63 MODULE_PARM_DESC(max_queues,
64 "Maximum number of queues per virtual interface");
65
66 static const struct ethtool_ops xennet_ethtool_ops;
67
68 struct netfront_cb {
69 int pull_to;
70 };
71
72 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
73
74 #define RX_COPY_THRESHOLD 256
75
76 #define GRANT_INVALID_REF 0
77
78 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
79 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
80
81 /* Minimum number of Rx slots (includes slot for GSO metadata). */
82 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
83
84 /* Queue name is interface name with "-qNNN" appended */
85 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
86
87 /* IRQ name is queue name with "-tx" or "-rx" appended */
88 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
89
90 struct netfront_stats {
91 u64 rx_packets;
92 u64 tx_packets;
93 u64 rx_bytes;
94 u64 tx_bytes;
95 struct u64_stats_sync syncp;
96 };
97
98 struct netfront_info;
99
100 struct netfront_queue {
101 unsigned int id; /* Queue ID, 0-based */
102 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
103 struct netfront_info *info;
104
105 struct napi_struct napi;
106
107 /* Split event channels support, tx_* == rx_* when using
108 * single event channel.
109 */
110 unsigned int tx_evtchn, rx_evtchn;
111 unsigned int tx_irq, rx_irq;
112 /* Only used when split event channels support is enabled */
113 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
114 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
115
116 spinlock_t tx_lock;
117 struct xen_netif_tx_front_ring tx;
118 int tx_ring_ref;
119
120 /*
121 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
122 * are linked from tx_skb_freelist through skb_entry.link.
123 *
124 * NB. Freelist index entries are always going to be less than
125 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
126 * greater than PAGE_OFFSET: we use this property to distinguish
127 * them.
128 */
129 union skb_entry {
130 struct sk_buff *skb;
131 unsigned long link;
132 } tx_skbs[NET_TX_RING_SIZE];
133 grant_ref_t gref_tx_head;
134 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
135 struct page *grant_tx_page[NET_TX_RING_SIZE];
136 unsigned tx_skb_freelist;
137
138 spinlock_t rx_lock ____cacheline_aligned_in_smp;
139 struct xen_netif_rx_front_ring rx;
140 int rx_ring_ref;
141
142 struct timer_list rx_refill_timer;
143
144 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
145 grant_ref_t gref_rx_head;
146 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
147
148 unsigned long rx_pfn_array[NET_RX_RING_SIZE];
149 struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
150 struct mmu_update rx_mmu[NET_RX_RING_SIZE];
151 };
152
153 struct netfront_info {
154 struct list_head list;
155 struct net_device *netdev;
156
157 struct xenbus_device *xbdev;
158
159 /* Multi-queue support */
160 struct netfront_queue *queues;
161
162 /* Statistics */
163 struct netfront_stats __percpu *stats;
164
165 atomic_t rx_gso_checksum_fixup;
166 };
167
168 struct netfront_rx_info {
169 struct xen_netif_rx_response rx;
170 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
171 };
172
173 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
174 {
175 list->link = id;
176 }
177
178 static int skb_entry_is_link(const union skb_entry *list)
179 {
180 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
181 return (unsigned long)list->skb < PAGE_OFFSET;
182 }
183
184 /*
185 * Access macros for acquiring freeing slots in tx_skbs[].
186 */
187
188 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
189 unsigned short id)
190 {
191 skb_entry_set_link(&list[id], *head);
192 *head = id;
193 }
194
195 static unsigned short get_id_from_freelist(unsigned *head,
196 union skb_entry *list)
197 {
198 unsigned int id = *head;
199 *head = list[id].link;
200 return id;
201 }
202
203 static int xennet_rxidx(RING_IDX idx)
204 {
205 return idx & (NET_RX_RING_SIZE - 1);
206 }
207
208 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
209 RING_IDX ri)
210 {
211 int i = xennet_rxidx(ri);
212 struct sk_buff *skb = queue->rx_skbs[i];
213 queue->rx_skbs[i] = NULL;
214 return skb;
215 }
216
217 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
218 RING_IDX ri)
219 {
220 int i = xennet_rxidx(ri);
221 grant_ref_t ref = queue->grant_rx_ref[i];
222 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
223 return ref;
224 }
225
226 #ifdef CONFIG_SYSFS
227 static int xennet_sysfs_addif(struct net_device *netdev);
228 static void xennet_sysfs_delif(struct net_device *netdev);
229 #else /* !CONFIG_SYSFS */
230 #define xennet_sysfs_addif(dev) (0)
231 #define xennet_sysfs_delif(dev) do { } while (0)
232 #endif
233
234 static bool xennet_can_sg(struct net_device *dev)
235 {
236 return dev->features & NETIF_F_SG;
237 }
238
239
240 static void rx_refill_timeout(unsigned long data)
241 {
242 struct netfront_queue *queue = (struct netfront_queue *)data;
243 napi_schedule(&queue->napi);
244 }
245
246 static int netfront_tx_slot_available(struct netfront_queue *queue)
247 {
248 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
249 (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
250 }
251
252 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
253 {
254 struct net_device *dev = queue->info->netdev;
255 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
256
257 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
258 netfront_tx_slot_available(queue) &&
259 likely(netif_running(dev)))
260 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
261 }
262
263
264 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
265 {
266 struct sk_buff *skb;
267 struct page *page;
268
269 skb = __netdev_alloc_skb(queue->info->netdev,
270 RX_COPY_THRESHOLD + NET_IP_ALIGN,
271 GFP_ATOMIC | __GFP_NOWARN);
272 if (unlikely(!skb))
273 return NULL;
274
275 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
276 if (!page) {
277 kfree_skb(skb);
278 return NULL;
279 }
280 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
281
282 /* Align ip header to a 16 bytes boundary */
283 skb_reserve(skb, NET_IP_ALIGN);
284 skb->dev = queue->info->netdev;
285
286 return skb;
287 }
288
289
290 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
291 {
292 RING_IDX req_prod = queue->rx.req_prod_pvt;
293 int notify;
294
295 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
296 return;
297
298 for (req_prod = queue->rx.req_prod_pvt;
299 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
300 req_prod++) {
301 struct sk_buff *skb;
302 unsigned short id;
303 grant_ref_t ref;
304 unsigned long pfn;
305 struct xen_netif_rx_request *req;
306
307 skb = xennet_alloc_one_rx_buffer(queue);
308 if (!skb)
309 break;
310
311 id = xennet_rxidx(req_prod);
312
313 BUG_ON(queue->rx_skbs[id]);
314 queue->rx_skbs[id] = skb;
315
316 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
317 BUG_ON((signed short)ref < 0);
318 queue->grant_rx_ref[id] = ref;
319
320 pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
321
322 req = RING_GET_REQUEST(&queue->rx, req_prod);
323 gnttab_grant_foreign_access_ref(ref,
324 queue->info->xbdev->otherend_id,
325 pfn_to_mfn(pfn),
326 0);
327
328 req->id = id;
329 req->gref = ref;
330 }
331
332 queue->rx.req_prod_pvt = req_prod;
333
334 /* Not enough requests? Try again later. */
335 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) {
336 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
337 return;
338 }
339
340 wmb(); /* barrier so backend seens requests */
341
342 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
343 if (notify)
344 notify_remote_via_irq(queue->rx_irq);
345 }
346
347 static int xennet_open(struct net_device *dev)
348 {
349 struct netfront_info *np = netdev_priv(dev);
350 unsigned int num_queues = dev->real_num_tx_queues;
351 unsigned int i = 0;
352 struct netfront_queue *queue = NULL;
353
354 for (i = 0; i < num_queues; ++i) {
355 queue = &np->queues[i];
356 napi_enable(&queue->napi);
357
358 spin_lock_bh(&queue->rx_lock);
359 if (netif_carrier_ok(dev)) {
360 xennet_alloc_rx_buffers(queue);
361 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
362 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
363 napi_schedule(&queue->napi);
364 }
365 spin_unlock_bh(&queue->rx_lock);
366 }
367
368 netif_tx_start_all_queues(dev);
369
370 return 0;
371 }
372
373 static void xennet_tx_buf_gc(struct netfront_queue *queue)
374 {
375 RING_IDX cons, prod;
376 unsigned short id;
377 struct sk_buff *skb;
378
379 BUG_ON(!netif_carrier_ok(queue->info->netdev));
380
381 do {
382 prod = queue->tx.sring->rsp_prod;
383 rmb(); /* Ensure we see responses up to 'rp'. */
384
385 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
386 struct xen_netif_tx_response *txrsp;
387
388 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
389 if (txrsp->status == XEN_NETIF_RSP_NULL)
390 continue;
391
392 id = txrsp->id;
393 skb = queue->tx_skbs[id].skb;
394 if (unlikely(gnttab_query_foreign_access(
395 queue->grant_tx_ref[id]) != 0)) {
396 pr_alert("%s: warning -- grant still in use by backend domain\n",
397 __func__);
398 BUG();
399 }
400 gnttab_end_foreign_access_ref(
401 queue->grant_tx_ref[id], GNTMAP_readonly);
402 gnttab_release_grant_reference(
403 &queue->gref_tx_head, queue->grant_tx_ref[id]);
404 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
405 queue->grant_tx_page[id] = NULL;
406 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
407 dev_kfree_skb_irq(skb);
408 }
409
410 queue->tx.rsp_cons = prod;
411
412 /*
413 * Set a new event, then check for race with update of tx_cons.
414 * Note that it is essential to schedule a callback, no matter
415 * how few buffers are pending. Even if there is space in the
416 * transmit ring, higher layers may be blocked because too much
417 * data is outstanding: in such cases notification from Xen is
418 * likely to be the only kick that we'll get.
419 */
420 queue->tx.sring->rsp_event =
421 prod + ((queue->tx.sring->req_prod - prod) >> 1) + 1;
422 mb(); /* update shared area */
423 } while ((cons == prod) && (prod != queue->tx.sring->rsp_prod));
424
425 xennet_maybe_wake_tx(queue);
426 }
427
428 static void xennet_make_frags(struct sk_buff *skb, struct netfront_queue *queue,
429 struct xen_netif_tx_request *tx)
430 {
431 char *data = skb->data;
432 unsigned long mfn;
433 RING_IDX prod = queue->tx.req_prod_pvt;
434 int frags = skb_shinfo(skb)->nr_frags;
435 unsigned int offset = offset_in_page(data);
436 unsigned int len = skb_headlen(skb);
437 unsigned int id;
438 grant_ref_t ref;
439 int i;
440
441 /* While the header overlaps a page boundary (including being
442 larger than a page), split it it into page-sized chunks. */
443 while (len > PAGE_SIZE - offset) {
444 tx->size = PAGE_SIZE - offset;
445 tx->flags |= XEN_NETTXF_more_data;
446 len -= tx->size;
447 data += tx->size;
448 offset = 0;
449
450 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
451 queue->tx_skbs[id].skb = skb_get(skb);
452 tx = RING_GET_REQUEST(&queue->tx, prod++);
453 tx->id = id;
454 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
455 BUG_ON((signed short)ref < 0);
456
457 mfn = virt_to_mfn(data);
458 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
459 mfn, GNTMAP_readonly);
460
461 queue->grant_tx_page[id] = virt_to_page(data);
462 tx->gref = queue->grant_tx_ref[id] = ref;
463 tx->offset = offset;
464 tx->size = len;
465 tx->flags = 0;
466 }
467
468 /* Grant backend access to each skb fragment page. */
469 for (i = 0; i < frags; i++) {
470 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
471 struct page *page = skb_frag_page(frag);
472
473 len = skb_frag_size(frag);
474 offset = frag->page_offset;
475
476 /* Data must not cross a page boundary. */
477 BUG_ON(len + offset > PAGE_SIZE<<compound_order(page));
478
479 /* Skip unused frames from start of page */
480 page += offset >> PAGE_SHIFT;
481 offset &= ~PAGE_MASK;
482
483 while (len > 0) {
484 unsigned long bytes;
485
486 BUG_ON(offset >= PAGE_SIZE);
487
488 bytes = PAGE_SIZE - offset;
489 if (bytes > len)
490 bytes = len;
491
492 tx->flags |= XEN_NETTXF_more_data;
493
494 id = get_id_from_freelist(&queue->tx_skb_freelist,
495 queue->tx_skbs);
496 queue->tx_skbs[id].skb = skb_get(skb);
497 tx = RING_GET_REQUEST(&queue->tx, prod++);
498 tx->id = id;
499 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
500 BUG_ON((signed short)ref < 0);
501
502 mfn = pfn_to_mfn(page_to_pfn(page));
503 gnttab_grant_foreign_access_ref(ref,
504 queue->info->xbdev->otherend_id,
505 mfn, GNTMAP_readonly);
506
507 queue->grant_tx_page[id] = page;
508 tx->gref = queue->grant_tx_ref[id] = ref;
509 tx->offset = offset;
510 tx->size = bytes;
511 tx->flags = 0;
512
513 offset += bytes;
514 len -= bytes;
515
516 /* Next frame */
517 if (offset == PAGE_SIZE && len) {
518 BUG_ON(!PageCompound(page));
519 page++;
520 offset = 0;
521 }
522 }
523 }
524
525 queue->tx.req_prod_pvt = prod;
526 }
527
528 /*
529 * Count how many ring slots are required to send the frags of this
530 * skb. Each frag might be a compound page.
531 */
532 static int xennet_count_skb_frag_slots(struct sk_buff *skb)
533 {
534 int i, frags = skb_shinfo(skb)->nr_frags;
535 int pages = 0;
536
537 for (i = 0; i < frags; i++) {
538 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
539 unsigned long size = skb_frag_size(frag);
540 unsigned long offset = frag->page_offset;
541
542 /* Skip unused frames from start of page */
543 offset &= ~PAGE_MASK;
544
545 pages += PFN_UP(offset + size);
546 }
547
548 return pages;
549 }
550
551 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
552 void *accel_priv, select_queue_fallback_t fallback)
553 {
554 unsigned int num_queues = dev->real_num_tx_queues;
555 u32 hash;
556 u16 queue_idx;
557
558 /* First, check if there is only one queue */
559 if (num_queues == 1) {
560 queue_idx = 0;
561 } else {
562 hash = skb_get_hash(skb);
563 queue_idx = hash % num_queues;
564 }
565
566 return queue_idx;
567 }
568
569 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
570 {
571 unsigned short id;
572 struct netfront_info *np = netdev_priv(dev);
573 struct netfront_stats *stats = this_cpu_ptr(np->stats);
574 struct xen_netif_tx_request *tx;
575 char *data = skb->data;
576 RING_IDX i;
577 grant_ref_t ref;
578 unsigned long mfn;
579 int notify;
580 int slots;
581 unsigned int offset = offset_in_page(data);
582 unsigned int len = skb_headlen(skb);
583 unsigned long flags;
584 struct netfront_queue *queue = NULL;
585 unsigned int num_queues = dev->real_num_tx_queues;
586 u16 queue_index;
587
588 /* Drop the packet if no queues are set up */
589 if (num_queues < 1)
590 goto drop;
591 /* Determine which queue to transmit this SKB on */
592 queue_index = skb_get_queue_mapping(skb);
593 queue = &np->queues[queue_index];
594
595 /* If skb->len is too big for wire format, drop skb and alert
596 * user about misconfiguration.
597 */
598 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
599 net_alert_ratelimited(
600 "xennet: skb->len = %u, too big for wire format\n",
601 skb->len);
602 goto drop;
603 }
604
605 slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
606 xennet_count_skb_frag_slots(skb);
607 if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
608 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
609 slots, skb->len);
610 if (skb_linearize(skb))
611 goto drop;
612 }
613
614 spin_lock_irqsave(&queue->tx_lock, flags);
615
616 if (unlikely(!netif_carrier_ok(dev) ||
617 (slots > 1 && !xennet_can_sg(dev)) ||
618 netif_needs_gso(dev, skb, netif_skb_features(skb)))) {
619 spin_unlock_irqrestore(&queue->tx_lock, flags);
620 goto drop;
621 }
622
623 i = queue->tx.req_prod_pvt;
624
625 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
626 queue->tx_skbs[id].skb = skb;
627
628 tx = RING_GET_REQUEST(&queue->tx, i);
629
630 tx->id = id;
631 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
632 BUG_ON((signed short)ref < 0);
633 mfn = virt_to_mfn(data);
634 gnttab_grant_foreign_access_ref(
635 ref, queue->info->xbdev->otherend_id, mfn, GNTMAP_readonly);
636 queue->grant_tx_page[id] = virt_to_page(data);
637 tx->gref = queue->grant_tx_ref[id] = ref;
638 tx->offset = offset;
639 tx->size = len;
640
641 tx->flags = 0;
642 if (skb->ip_summed == CHECKSUM_PARTIAL)
643 /* local packet? */
644 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
645 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
646 /* remote but checksummed. */
647 tx->flags |= XEN_NETTXF_data_validated;
648
649 if (skb_shinfo(skb)->gso_size) {
650 struct xen_netif_extra_info *gso;
651
652 gso = (struct xen_netif_extra_info *)
653 RING_GET_REQUEST(&queue->tx, ++i);
654
655 tx->flags |= XEN_NETTXF_extra_info;
656
657 gso->u.gso.size = skb_shinfo(skb)->gso_size;
658 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
659 XEN_NETIF_GSO_TYPE_TCPV6 :
660 XEN_NETIF_GSO_TYPE_TCPV4;
661 gso->u.gso.pad = 0;
662 gso->u.gso.features = 0;
663
664 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
665 gso->flags = 0;
666 }
667
668 queue->tx.req_prod_pvt = i + 1;
669
670 xennet_make_frags(skb, queue, tx);
671 tx->size = skb->len;
672
673 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
674 if (notify)
675 notify_remote_via_irq(queue->tx_irq);
676
677 u64_stats_update_begin(&stats->syncp);
678 stats->tx_bytes += skb->len;
679 stats->tx_packets++;
680 u64_stats_update_end(&stats->syncp);
681
682 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
683 xennet_tx_buf_gc(queue);
684
685 if (!netfront_tx_slot_available(queue))
686 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
687
688 spin_unlock_irqrestore(&queue->tx_lock, flags);
689
690 return NETDEV_TX_OK;
691
692 drop:
693 dev->stats.tx_dropped++;
694 dev_kfree_skb_any(skb);
695 return NETDEV_TX_OK;
696 }
697
698 static int xennet_close(struct net_device *dev)
699 {
700 struct netfront_info *np = netdev_priv(dev);
701 unsigned int num_queues = dev->real_num_tx_queues;
702 unsigned int i;
703 struct netfront_queue *queue;
704 netif_tx_stop_all_queues(np->netdev);
705 for (i = 0; i < num_queues; ++i) {
706 queue = &np->queues[i];
707 napi_disable(&queue->napi);
708 }
709 return 0;
710 }
711
712 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
713 grant_ref_t ref)
714 {
715 int new = xennet_rxidx(queue->rx.req_prod_pvt);
716
717 BUG_ON(queue->rx_skbs[new]);
718 queue->rx_skbs[new] = skb;
719 queue->grant_rx_ref[new] = ref;
720 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
721 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
722 queue->rx.req_prod_pvt++;
723 }
724
725 static int xennet_get_extras(struct netfront_queue *queue,
726 struct xen_netif_extra_info *extras,
727 RING_IDX rp)
728
729 {
730 struct xen_netif_extra_info *extra;
731 struct device *dev = &queue->info->netdev->dev;
732 RING_IDX cons = queue->rx.rsp_cons;
733 int err = 0;
734
735 do {
736 struct sk_buff *skb;
737 grant_ref_t ref;
738
739 if (unlikely(cons + 1 == rp)) {
740 if (net_ratelimit())
741 dev_warn(dev, "Missing extra info\n");
742 err = -EBADR;
743 break;
744 }
745
746 extra = (struct xen_netif_extra_info *)
747 RING_GET_RESPONSE(&queue->rx, ++cons);
748
749 if (unlikely(!extra->type ||
750 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
751 if (net_ratelimit())
752 dev_warn(dev, "Invalid extra type: %d\n",
753 extra->type);
754 err = -EINVAL;
755 } else {
756 memcpy(&extras[extra->type - 1], extra,
757 sizeof(*extra));
758 }
759
760 skb = xennet_get_rx_skb(queue, cons);
761 ref = xennet_get_rx_ref(queue, cons);
762 xennet_move_rx_slot(queue, skb, ref);
763 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
764
765 queue->rx.rsp_cons = cons;
766 return err;
767 }
768
769 static int xennet_get_responses(struct netfront_queue *queue,
770 struct netfront_rx_info *rinfo, RING_IDX rp,
771 struct sk_buff_head *list)
772 {
773 struct xen_netif_rx_response *rx = &rinfo->rx;
774 struct xen_netif_extra_info *extras = rinfo->extras;
775 struct device *dev = &queue->info->netdev->dev;
776 RING_IDX cons = queue->rx.rsp_cons;
777 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
778 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
779 int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
780 int slots = 1;
781 int err = 0;
782 unsigned long ret;
783
784 if (rx->flags & XEN_NETRXF_extra_info) {
785 err = xennet_get_extras(queue, extras, rp);
786 cons = queue->rx.rsp_cons;
787 }
788
789 for (;;) {
790 if (unlikely(rx->status < 0 ||
791 rx->offset + rx->status > PAGE_SIZE)) {
792 if (net_ratelimit())
793 dev_warn(dev, "rx->offset: %x, size: %u\n",
794 rx->offset, rx->status);
795 xennet_move_rx_slot(queue, skb, ref);
796 err = -EINVAL;
797 goto next;
798 }
799
800 /*
801 * This definitely indicates a bug, either in this driver or in
802 * the backend driver. In future this should flag the bad
803 * situation to the system controller to reboot the backend.
804 */
805 if (ref == GRANT_INVALID_REF) {
806 if (net_ratelimit())
807 dev_warn(dev, "Bad rx response id %d.\n",
808 rx->id);
809 err = -EINVAL;
810 goto next;
811 }
812
813 ret = gnttab_end_foreign_access_ref(ref, 0);
814 BUG_ON(!ret);
815
816 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
817
818 __skb_queue_tail(list, skb);
819
820 next:
821 if (!(rx->flags & XEN_NETRXF_more_data))
822 break;
823
824 if (cons + slots == rp) {
825 if (net_ratelimit())
826 dev_warn(dev, "Need more slots\n");
827 err = -ENOENT;
828 break;
829 }
830
831 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
832 skb = xennet_get_rx_skb(queue, cons + slots);
833 ref = xennet_get_rx_ref(queue, cons + slots);
834 slots++;
835 }
836
837 if (unlikely(slots > max)) {
838 if (net_ratelimit())
839 dev_warn(dev, "Too many slots\n");
840 err = -E2BIG;
841 }
842
843 if (unlikely(err))
844 queue->rx.rsp_cons = cons + slots;
845
846 return err;
847 }
848
849 static int xennet_set_skb_gso(struct sk_buff *skb,
850 struct xen_netif_extra_info *gso)
851 {
852 if (!gso->u.gso.size) {
853 if (net_ratelimit())
854 pr_warn("GSO size must not be zero\n");
855 return -EINVAL;
856 }
857
858 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
859 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
860 if (net_ratelimit())
861 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
862 return -EINVAL;
863 }
864
865 skb_shinfo(skb)->gso_size = gso->u.gso.size;
866 skb_shinfo(skb)->gso_type =
867 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
868 SKB_GSO_TCPV4 :
869 SKB_GSO_TCPV6;
870
871 /* Header must be checked, and gso_segs computed. */
872 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
873 skb_shinfo(skb)->gso_segs = 0;
874
875 return 0;
876 }
877
878 static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
879 struct sk_buff *skb,
880 struct sk_buff_head *list)
881 {
882 struct skb_shared_info *shinfo = skb_shinfo(skb);
883 RING_IDX cons = queue->rx.rsp_cons;
884 struct sk_buff *nskb;
885
886 while ((nskb = __skb_dequeue(list))) {
887 struct xen_netif_rx_response *rx =
888 RING_GET_RESPONSE(&queue->rx, ++cons);
889 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
890
891 if (shinfo->nr_frags == MAX_SKB_FRAGS) {
892 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
893
894 BUG_ON(pull_to <= skb_headlen(skb));
895 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
896 }
897 BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
898
899 skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
900 rx->offset, rx->status, PAGE_SIZE);
901
902 skb_shinfo(nskb)->nr_frags = 0;
903 kfree_skb(nskb);
904 }
905
906 return cons;
907 }
908
909 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
910 {
911 bool recalculate_partial_csum = false;
912
913 /*
914 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
915 * peers can fail to set NETRXF_csum_blank when sending a GSO
916 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
917 * recalculate the partial checksum.
918 */
919 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
920 struct netfront_info *np = netdev_priv(dev);
921 atomic_inc(&np->rx_gso_checksum_fixup);
922 skb->ip_summed = CHECKSUM_PARTIAL;
923 recalculate_partial_csum = true;
924 }
925
926 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
927 if (skb->ip_summed != CHECKSUM_PARTIAL)
928 return 0;
929
930 return skb_checksum_setup(skb, recalculate_partial_csum);
931 }
932
933 static int handle_incoming_queue(struct netfront_queue *queue,
934 struct sk_buff_head *rxq)
935 {
936 struct netfront_stats *stats = this_cpu_ptr(queue->info->stats);
937 int packets_dropped = 0;
938 struct sk_buff *skb;
939
940 while ((skb = __skb_dequeue(rxq)) != NULL) {
941 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
942
943 if (pull_to > skb_headlen(skb))
944 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
945
946 /* Ethernet work: Delayed to here as it peeks the header. */
947 skb->protocol = eth_type_trans(skb, queue->info->netdev);
948 skb_reset_network_header(skb);
949
950 if (checksum_setup(queue->info->netdev, skb)) {
951 kfree_skb(skb);
952 packets_dropped++;
953 queue->info->netdev->stats.rx_errors++;
954 continue;
955 }
956
957 u64_stats_update_begin(&stats->syncp);
958 stats->rx_packets++;
959 stats->rx_bytes += skb->len;
960 u64_stats_update_end(&stats->syncp);
961
962 /* Pass it up. */
963 napi_gro_receive(&queue->napi, skb);
964 }
965
966 return packets_dropped;
967 }
968
969 static int xennet_poll(struct napi_struct *napi, int budget)
970 {
971 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
972 struct net_device *dev = queue->info->netdev;
973 struct sk_buff *skb;
974 struct netfront_rx_info rinfo;
975 struct xen_netif_rx_response *rx = &rinfo.rx;
976 struct xen_netif_extra_info *extras = rinfo.extras;
977 RING_IDX i, rp;
978 int work_done;
979 struct sk_buff_head rxq;
980 struct sk_buff_head errq;
981 struct sk_buff_head tmpq;
982 unsigned long flags;
983 int err;
984
985 spin_lock(&queue->rx_lock);
986
987 skb_queue_head_init(&rxq);
988 skb_queue_head_init(&errq);
989 skb_queue_head_init(&tmpq);
990
991 rp = queue->rx.sring->rsp_prod;
992 rmb(); /* Ensure we see queued responses up to 'rp'. */
993
994 i = queue->rx.rsp_cons;
995 work_done = 0;
996 while ((i != rp) && (work_done < budget)) {
997 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
998 memset(extras, 0, sizeof(rinfo.extras));
999
1000 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1001
1002 if (unlikely(err)) {
1003 err:
1004 while ((skb = __skb_dequeue(&tmpq)))
1005 __skb_queue_tail(&errq, skb);
1006 dev->stats.rx_errors++;
1007 i = queue->rx.rsp_cons;
1008 continue;
1009 }
1010
1011 skb = __skb_dequeue(&tmpq);
1012
1013 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1014 struct xen_netif_extra_info *gso;
1015 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1016
1017 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1018 __skb_queue_head(&tmpq, skb);
1019 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1020 goto err;
1021 }
1022 }
1023
1024 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1025 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1026 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1027
1028 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1029 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1030 skb->data_len = rx->status;
1031 skb->len += rx->status;
1032
1033 i = xennet_fill_frags(queue, skb, &tmpq);
1034
1035 if (rx->flags & XEN_NETRXF_csum_blank)
1036 skb->ip_summed = CHECKSUM_PARTIAL;
1037 else if (rx->flags & XEN_NETRXF_data_validated)
1038 skb->ip_summed = CHECKSUM_UNNECESSARY;
1039
1040 __skb_queue_tail(&rxq, skb);
1041
1042 queue->rx.rsp_cons = ++i;
1043 work_done++;
1044 }
1045
1046 __skb_queue_purge(&errq);
1047
1048 work_done -= handle_incoming_queue(queue, &rxq);
1049
1050 xennet_alloc_rx_buffers(queue);
1051
1052 if (work_done < budget) {
1053 int more_to_do = 0;
1054
1055 napi_gro_flush(napi, false);
1056
1057 local_irq_save(flags);
1058
1059 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1060 if (!more_to_do)
1061 __napi_complete(napi);
1062
1063 local_irq_restore(flags);
1064 }
1065
1066 spin_unlock(&queue->rx_lock);
1067
1068 return work_done;
1069 }
1070
1071 static int xennet_change_mtu(struct net_device *dev, int mtu)
1072 {
1073 int max = xennet_can_sg(dev) ?
1074 XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN;
1075
1076 if (mtu > max)
1077 return -EINVAL;
1078 dev->mtu = mtu;
1079 return 0;
1080 }
1081
1082 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1083 struct rtnl_link_stats64 *tot)
1084 {
1085 struct netfront_info *np = netdev_priv(dev);
1086 int cpu;
1087
1088 for_each_possible_cpu(cpu) {
1089 struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
1090 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1091 unsigned int start;
1092
1093 do {
1094 start = u64_stats_fetch_begin_irq(&stats->syncp);
1095
1096 rx_packets = stats->rx_packets;
1097 tx_packets = stats->tx_packets;
1098 rx_bytes = stats->rx_bytes;
1099 tx_bytes = stats->tx_bytes;
1100 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
1101
1102 tot->rx_packets += rx_packets;
1103 tot->tx_packets += tx_packets;
1104 tot->rx_bytes += rx_bytes;
1105 tot->tx_bytes += tx_bytes;
1106 }
1107
1108 tot->rx_errors = dev->stats.rx_errors;
1109 tot->tx_dropped = dev->stats.tx_dropped;
1110
1111 return tot;
1112 }
1113
1114 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1115 {
1116 struct sk_buff *skb;
1117 int i;
1118
1119 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1120 /* Skip over entries which are actually freelist references */
1121 if (skb_entry_is_link(&queue->tx_skbs[i]))
1122 continue;
1123
1124 skb = queue->tx_skbs[i].skb;
1125 get_page(queue->grant_tx_page[i]);
1126 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1127 GNTMAP_readonly,
1128 (unsigned long)page_address(queue->grant_tx_page[i]));
1129 queue->grant_tx_page[i] = NULL;
1130 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1131 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1132 dev_kfree_skb_irq(skb);
1133 }
1134 }
1135
1136 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1137 {
1138 int id, ref;
1139
1140 spin_lock_bh(&queue->rx_lock);
1141
1142 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1143 struct sk_buff *skb;
1144 struct page *page;
1145
1146 skb = queue->rx_skbs[id];
1147 if (!skb)
1148 continue;
1149
1150 ref = queue->grant_rx_ref[id];
1151 if (ref == GRANT_INVALID_REF)
1152 continue;
1153
1154 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1155
1156 /* gnttab_end_foreign_access() needs a page ref until
1157 * foreign access is ended (which may be deferred).
1158 */
1159 get_page(page);
1160 gnttab_end_foreign_access(ref, 0,
1161 (unsigned long)page_address(page));
1162 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1163
1164 kfree_skb(skb);
1165 }
1166
1167 spin_unlock_bh(&queue->rx_lock);
1168 }
1169
1170 static netdev_features_t xennet_fix_features(struct net_device *dev,
1171 netdev_features_t features)
1172 {
1173 struct netfront_info *np = netdev_priv(dev);
1174 int val;
1175
1176 if (features & NETIF_F_SG) {
1177 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1178 "%d", &val) < 0)
1179 val = 0;
1180
1181 if (!val)
1182 features &= ~NETIF_F_SG;
1183 }
1184
1185 if (features & NETIF_F_IPV6_CSUM) {
1186 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1187 "feature-ipv6-csum-offload", "%d", &val) < 0)
1188 val = 0;
1189
1190 if (!val)
1191 features &= ~NETIF_F_IPV6_CSUM;
1192 }
1193
1194 if (features & NETIF_F_TSO) {
1195 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1196 "feature-gso-tcpv4", "%d", &val) < 0)
1197 val = 0;
1198
1199 if (!val)
1200 features &= ~NETIF_F_TSO;
1201 }
1202
1203 if (features & NETIF_F_TSO6) {
1204 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1205 "feature-gso-tcpv6", "%d", &val) < 0)
1206 val = 0;
1207
1208 if (!val)
1209 features &= ~NETIF_F_TSO6;
1210 }
1211
1212 return features;
1213 }
1214
1215 static int xennet_set_features(struct net_device *dev,
1216 netdev_features_t features)
1217 {
1218 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1219 netdev_info(dev, "Reducing MTU because no SG offload");
1220 dev->mtu = ETH_DATA_LEN;
1221 }
1222
1223 return 0;
1224 }
1225
1226 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1227 {
1228 struct netfront_queue *queue = dev_id;
1229 unsigned long flags;
1230
1231 spin_lock_irqsave(&queue->tx_lock, flags);
1232 xennet_tx_buf_gc(queue);
1233 spin_unlock_irqrestore(&queue->tx_lock, flags);
1234
1235 return IRQ_HANDLED;
1236 }
1237
1238 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1239 {
1240 struct netfront_queue *queue = dev_id;
1241 struct net_device *dev = queue->info->netdev;
1242
1243 if (likely(netif_carrier_ok(dev) &&
1244 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1245 napi_schedule(&queue->napi);
1246
1247 return IRQ_HANDLED;
1248 }
1249
1250 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1251 {
1252 xennet_tx_interrupt(irq, dev_id);
1253 xennet_rx_interrupt(irq, dev_id);
1254 return IRQ_HANDLED;
1255 }
1256
1257 #ifdef CONFIG_NET_POLL_CONTROLLER
1258 static void xennet_poll_controller(struct net_device *dev)
1259 {
1260 /* Poll each queue */
1261 struct netfront_info *info = netdev_priv(dev);
1262 unsigned int num_queues = dev->real_num_tx_queues;
1263 unsigned int i;
1264 for (i = 0; i < num_queues; ++i)
1265 xennet_interrupt(0, &info->queues[i]);
1266 }
1267 #endif
1268
1269 static const struct net_device_ops xennet_netdev_ops = {
1270 .ndo_open = xennet_open,
1271 .ndo_stop = xennet_close,
1272 .ndo_start_xmit = xennet_start_xmit,
1273 .ndo_change_mtu = xennet_change_mtu,
1274 .ndo_get_stats64 = xennet_get_stats64,
1275 .ndo_set_mac_address = eth_mac_addr,
1276 .ndo_validate_addr = eth_validate_addr,
1277 .ndo_fix_features = xennet_fix_features,
1278 .ndo_set_features = xennet_set_features,
1279 .ndo_select_queue = xennet_select_queue,
1280 #ifdef CONFIG_NET_POLL_CONTROLLER
1281 .ndo_poll_controller = xennet_poll_controller,
1282 #endif
1283 };
1284
1285 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1286 {
1287 int err;
1288 struct net_device *netdev;
1289 struct netfront_info *np;
1290
1291 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1292 if (!netdev)
1293 return ERR_PTR(-ENOMEM);
1294
1295 np = netdev_priv(netdev);
1296 np->xbdev = dev;
1297
1298 /* No need to use rtnl_lock() before the call below as it
1299 * happens before register_netdev().
1300 */
1301 netif_set_real_num_tx_queues(netdev, 0);
1302 np->queues = NULL;
1303
1304 err = -ENOMEM;
1305 np->stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1306 if (np->stats == NULL)
1307 goto exit;
1308
1309 netdev->netdev_ops = &xennet_netdev_ops;
1310
1311 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1312 NETIF_F_GSO_ROBUST;
1313 netdev->hw_features = NETIF_F_SG |
1314 NETIF_F_IPV6_CSUM |
1315 NETIF_F_TSO | NETIF_F_TSO6;
1316
1317 /*
1318 * Assume that all hw features are available for now. This set
1319 * will be adjusted by the call to netdev_update_features() in
1320 * xennet_connect() which is the earliest point where we can
1321 * negotiate with the backend regarding supported features.
1322 */
1323 netdev->features |= netdev->hw_features;
1324
1325 netdev->ethtool_ops = &xennet_ethtool_ops;
1326 SET_NETDEV_DEV(netdev, &dev->dev);
1327
1328 netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER);
1329
1330 np->netdev = netdev;
1331
1332 netif_carrier_off(netdev);
1333
1334 return netdev;
1335
1336 exit:
1337 free_netdev(netdev);
1338 return ERR_PTR(err);
1339 }
1340
1341 /**
1342 * Entry point to this code when a new device is created. Allocate the basic
1343 * structures and the ring buffers for communication with the backend, and
1344 * inform the backend of the appropriate details for those.
1345 */
1346 static int netfront_probe(struct xenbus_device *dev,
1347 const struct xenbus_device_id *id)
1348 {
1349 int err;
1350 struct net_device *netdev;
1351 struct netfront_info *info;
1352
1353 netdev = xennet_create_dev(dev);
1354 if (IS_ERR(netdev)) {
1355 err = PTR_ERR(netdev);
1356 xenbus_dev_fatal(dev, err, "creating netdev");
1357 return err;
1358 }
1359
1360 info = netdev_priv(netdev);
1361 dev_set_drvdata(&dev->dev, info);
1362
1363 err = register_netdev(info->netdev);
1364 if (err) {
1365 pr_warn("%s: register_netdev err=%d\n", __func__, err);
1366 goto fail;
1367 }
1368
1369 err = xennet_sysfs_addif(info->netdev);
1370 if (err) {
1371 unregister_netdev(info->netdev);
1372 pr_warn("%s: add sysfs failed err=%d\n", __func__, err);
1373 goto fail;
1374 }
1375
1376 return 0;
1377
1378 fail:
1379 free_netdev(netdev);
1380 dev_set_drvdata(&dev->dev, NULL);
1381 return err;
1382 }
1383
1384 static void xennet_end_access(int ref, void *page)
1385 {
1386 /* This frees the page as a side-effect */
1387 if (ref != GRANT_INVALID_REF)
1388 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1389 }
1390
1391 static void xennet_disconnect_backend(struct netfront_info *info)
1392 {
1393 unsigned int i = 0;
1394 unsigned int num_queues = info->netdev->real_num_tx_queues;
1395
1396 netif_carrier_off(info->netdev);
1397
1398 for (i = 0; i < num_queues; ++i) {
1399 struct netfront_queue *queue = &info->queues[i];
1400
1401 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1402 unbind_from_irqhandler(queue->tx_irq, queue);
1403 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1404 unbind_from_irqhandler(queue->tx_irq, queue);
1405 unbind_from_irqhandler(queue->rx_irq, queue);
1406 }
1407 queue->tx_evtchn = queue->rx_evtchn = 0;
1408 queue->tx_irq = queue->rx_irq = 0;
1409
1410 napi_synchronize(&queue->napi);
1411
1412 xennet_release_tx_bufs(queue);
1413 xennet_release_rx_bufs(queue);
1414 gnttab_free_grant_references(queue->gref_tx_head);
1415 gnttab_free_grant_references(queue->gref_rx_head);
1416
1417 /* End access and free the pages */
1418 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1419 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1420
1421 queue->tx_ring_ref = GRANT_INVALID_REF;
1422 queue->rx_ring_ref = GRANT_INVALID_REF;
1423 queue->tx.sring = NULL;
1424 queue->rx.sring = NULL;
1425 }
1426 }
1427
1428 /**
1429 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1430 * driver restart. We tear down our netif structure and recreate it, but
1431 * leave the device-layer structures intact so that this is transparent to the
1432 * rest of the kernel.
1433 */
1434 static int netfront_resume(struct xenbus_device *dev)
1435 {
1436 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1437
1438 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1439
1440 xennet_disconnect_backend(info);
1441 return 0;
1442 }
1443
1444 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1445 {
1446 char *s, *e, *macstr;
1447 int i;
1448
1449 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1450 if (IS_ERR(macstr))
1451 return PTR_ERR(macstr);
1452
1453 for (i = 0; i < ETH_ALEN; i++) {
1454 mac[i] = simple_strtoul(s, &e, 16);
1455 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1456 kfree(macstr);
1457 return -ENOENT;
1458 }
1459 s = e+1;
1460 }
1461
1462 kfree(macstr);
1463 return 0;
1464 }
1465
1466 static int setup_netfront_single(struct netfront_queue *queue)
1467 {
1468 int err;
1469
1470 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1471 if (err < 0)
1472 goto fail;
1473
1474 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1475 xennet_interrupt,
1476 0, queue->info->netdev->name, queue);
1477 if (err < 0)
1478 goto bind_fail;
1479 queue->rx_evtchn = queue->tx_evtchn;
1480 queue->rx_irq = queue->tx_irq = err;
1481
1482 return 0;
1483
1484 bind_fail:
1485 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1486 queue->tx_evtchn = 0;
1487 fail:
1488 return err;
1489 }
1490
1491 static int setup_netfront_split(struct netfront_queue *queue)
1492 {
1493 int err;
1494
1495 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1496 if (err < 0)
1497 goto fail;
1498 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1499 if (err < 0)
1500 goto alloc_rx_evtchn_fail;
1501
1502 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1503 "%s-tx", queue->name);
1504 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1505 xennet_tx_interrupt,
1506 0, queue->tx_irq_name, queue);
1507 if (err < 0)
1508 goto bind_tx_fail;
1509 queue->tx_irq = err;
1510
1511 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1512 "%s-rx", queue->name);
1513 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1514 xennet_rx_interrupt,
1515 0, queue->rx_irq_name, queue);
1516 if (err < 0)
1517 goto bind_rx_fail;
1518 queue->rx_irq = err;
1519
1520 return 0;
1521
1522 bind_rx_fail:
1523 unbind_from_irqhandler(queue->tx_irq, queue);
1524 queue->tx_irq = 0;
1525 bind_tx_fail:
1526 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1527 queue->rx_evtchn = 0;
1528 alloc_rx_evtchn_fail:
1529 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1530 queue->tx_evtchn = 0;
1531 fail:
1532 return err;
1533 }
1534
1535 static int setup_netfront(struct xenbus_device *dev,
1536 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1537 {
1538 struct xen_netif_tx_sring *txs;
1539 struct xen_netif_rx_sring *rxs;
1540 int err;
1541
1542 queue->tx_ring_ref = GRANT_INVALID_REF;
1543 queue->rx_ring_ref = GRANT_INVALID_REF;
1544 queue->rx.sring = NULL;
1545 queue->tx.sring = NULL;
1546
1547 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1548 if (!txs) {
1549 err = -ENOMEM;
1550 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1551 goto fail;
1552 }
1553 SHARED_RING_INIT(txs);
1554 FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE);
1555
1556 err = xenbus_grant_ring(dev, virt_to_mfn(txs));
1557 if (err < 0)
1558 goto grant_tx_ring_fail;
1559 queue->tx_ring_ref = err;
1560
1561 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1562 if (!rxs) {
1563 err = -ENOMEM;
1564 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1565 goto alloc_rx_ring_fail;
1566 }
1567 SHARED_RING_INIT(rxs);
1568 FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
1569
1570 err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
1571 if (err < 0)
1572 goto grant_rx_ring_fail;
1573 queue->rx_ring_ref = err;
1574
1575 if (feature_split_evtchn)
1576 err = setup_netfront_split(queue);
1577 /* setup single event channel if
1578 * a) feature-split-event-channels == 0
1579 * b) feature-split-event-channels == 1 but failed to setup
1580 */
1581 if (!feature_split_evtchn || (feature_split_evtchn && err))
1582 err = setup_netfront_single(queue);
1583
1584 if (err)
1585 goto alloc_evtchn_fail;
1586
1587 return 0;
1588
1589 /* If we fail to setup netfront, it is safe to just revoke access to
1590 * granted pages because backend is not accessing it at this point.
1591 */
1592 alloc_evtchn_fail:
1593 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1594 grant_rx_ring_fail:
1595 free_page((unsigned long)rxs);
1596 alloc_rx_ring_fail:
1597 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1598 grant_tx_ring_fail:
1599 free_page((unsigned long)txs);
1600 fail:
1601 return err;
1602 }
1603
1604 /* Queue-specific initialisation
1605 * This used to be done in xennet_create_dev() but must now
1606 * be run per-queue.
1607 */
1608 static int xennet_init_queue(struct netfront_queue *queue)
1609 {
1610 unsigned short i;
1611 int err = 0;
1612
1613 spin_lock_init(&queue->tx_lock);
1614 spin_lock_init(&queue->rx_lock);
1615
1616 init_timer(&queue->rx_refill_timer);
1617 queue->rx_refill_timer.data = (unsigned long)queue;
1618 queue->rx_refill_timer.function = rx_refill_timeout;
1619
1620 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
1621 queue->info->netdev->name, queue->id);
1622
1623 /* Initialise tx_skbs as a free chain containing every entry. */
1624 queue->tx_skb_freelist = 0;
1625 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1626 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1627 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1628 queue->grant_tx_page[i] = NULL;
1629 }
1630
1631 /* Clear out rx_skbs */
1632 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1633 queue->rx_skbs[i] = NULL;
1634 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1635 }
1636
1637 /* A grant for every tx ring slot */
1638 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1639 &queue->gref_tx_head) < 0) {
1640 pr_alert("can't alloc tx grant refs\n");
1641 err = -ENOMEM;
1642 goto exit;
1643 }
1644
1645 /* A grant for every rx ring slot */
1646 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1647 &queue->gref_rx_head) < 0) {
1648 pr_alert("can't alloc rx grant refs\n");
1649 err = -ENOMEM;
1650 goto exit_free_tx;
1651 }
1652
1653 return 0;
1654
1655 exit_free_tx:
1656 gnttab_free_grant_references(queue->gref_tx_head);
1657 exit:
1658 return err;
1659 }
1660
1661 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1662 struct xenbus_transaction *xbt, int write_hierarchical)
1663 {
1664 /* Write the queue-specific keys into XenStore in the traditional
1665 * way for a single queue, or in a queue subkeys for multiple
1666 * queues.
1667 */
1668 struct xenbus_device *dev = queue->info->xbdev;
1669 int err;
1670 const char *message;
1671 char *path;
1672 size_t pathsize;
1673
1674 /* Choose the correct place to write the keys */
1675 if (write_hierarchical) {
1676 pathsize = strlen(dev->nodename) + 10;
1677 path = kzalloc(pathsize, GFP_KERNEL);
1678 if (!path) {
1679 err = -ENOMEM;
1680 message = "out of memory while writing ring references";
1681 goto error;
1682 }
1683 snprintf(path, pathsize, "%s/queue-%u",
1684 dev->nodename, queue->id);
1685 } else {
1686 path = (char *)dev->nodename;
1687 }
1688
1689 /* Write ring references */
1690 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1691 queue->tx_ring_ref);
1692 if (err) {
1693 message = "writing tx-ring-ref";
1694 goto error;
1695 }
1696
1697 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1698 queue->rx_ring_ref);
1699 if (err) {
1700 message = "writing rx-ring-ref";
1701 goto error;
1702 }
1703
1704 /* Write event channels; taking into account both shared
1705 * and split event channel scenarios.
1706 */
1707 if (queue->tx_evtchn == queue->rx_evtchn) {
1708 /* Shared event channel */
1709 err = xenbus_printf(*xbt, path,
1710 "event-channel", "%u", queue->tx_evtchn);
1711 if (err) {
1712 message = "writing event-channel";
1713 goto error;
1714 }
1715 } else {
1716 /* Split event channels */
1717 err = xenbus_printf(*xbt, path,
1718 "event-channel-tx", "%u", queue->tx_evtchn);
1719 if (err) {
1720 message = "writing event-channel-tx";
1721 goto error;
1722 }
1723
1724 err = xenbus_printf(*xbt, path,
1725 "event-channel-rx", "%u", queue->rx_evtchn);
1726 if (err) {
1727 message = "writing event-channel-rx";
1728 goto error;
1729 }
1730 }
1731
1732 if (write_hierarchical)
1733 kfree(path);
1734 return 0;
1735
1736 error:
1737 if (write_hierarchical)
1738 kfree(path);
1739 xenbus_dev_fatal(dev, err, "%s", message);
1740 return err;
1741 }
1742
1743 static void xennet_destroy_queues(struct netfront_info *info)
1744 {
1745 unsigned int i;
1746
1747 rtnl_lock();
1748
1749 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1750 struct netfront_queue *queue = &info->queues[i];
1751
1752 if (netif_running(info->netdev))
1753 napi_disable(&queue->napi);
1754 netif_napi_del(&queue->napi);
1755 }
1756
1757 rtnl_unlock();
1758
1759 kfree(info->queues);
1760 info->queues = NULL;
1761 }
1762
1763 static int xennet_create_queues(struct netfront_info *info,
1764 unsigned int num_queues)
1765 {
1766 unsigned int i;
1767 int ret;
1768
1769 info->queues = kcalloc(num_queues, sizeof(struct netfront_queue),
1770 GFP_KERNEL);
1771 if (!info->queues)
1772 return -ENOMEM;
1773
1774 rtnl_lock();
1775
1776 for (i = 0; i < num_queues; i++) {
1777 struct netfront_queue *queue = &info->queues[i];
1778
1779 queue->id = i;
1780 queue->info = info;
1781
1782 ret = xennet_init_queue(queue);
1783 if (ret < 0) {
1784 dev_warn(&info->netdev->dev,
1785 "only created %d queues\n", i);
1786 num_queues = i;
1787 break;
1788 }
1789
1790 netif_napi_add(queue->info->netdev, &queue->napi,
1791 xennet_poll, 64);
1792 if (netif_running(info->netdev))
1793 napi_enable(&queue->napi);
1794 }
1795
1796 netif_set_real_num_tx_queues(info->netdev, num_queues);
1797
1798 rtnl_unlock();
1799
1800 if (num_queues == 0) {
1801 dev_err(&info->netdev->dev, "no queues\n");
1802 return -EINVAL;
1803 }
1804 return 0;
1805 }
1806
1807 /* Common code used when first setting up, and when resuming. */
1808 static int talk_to_netback(struct xenbus_device *dev,
1809 struct netfront_info *info)
1810 {
1811 const char *message;
1812 struct xenbus_transaction xbt;
1813 int err;
1814 unsigned int feature_split_evtchn;
1815 unsigned int i = 0;
1816 unsigned int max_queues = 0;
1817 struct netfront_queue *queue = NULL;
1818 unsigned int num_queues = 1;
1819
1820 info->netdev->irq = 0;
1821
1822 /* Check if backend supports multiple queues */
1823 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1824 "multi-queue-max-queues", "%u", &max_queues);
1825 if (err < 0)
1826 max_queues = 1;
1827 num_queues = min(max_queues, xennet_max_queues);
1828
1829 /* Check feature-split-event-channels */
1830 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1831 "feature-split-event-channels", "%u",
1832 &feature_split_evtchn);
1833 if (err < 0)
1834 feature_split_evtchn = 0;
1835
1836 /* Read mac addr. */
1837 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1838 if (err) {
1839 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1840 goto out;
1841 }
1842
1843 if (info->queues)
1844 xennet_destroy_queues(info);
1845
1846 err = xennet_create_queues(info, num_queues);
1847 if (err < 0)
1848 goto destroy_ring;
1849
1850 /* Create shared ring, alloc event channel -- for each queue */
1851 for (i = 0; i < num_queues; ++i) {
1852 queue = &info->queues[i];
1853 err = setup_netfront(dev, queue, feature_split_evtchn);
1854 if (err) {
1855 /* setup_netfront() will tidy up the current
1856 * queue on error, but we need to clean up
1857 * those already allocated.
1858 */
1859 if (i > 0) {
1860 rtnl_lock();
1861 netif_set_real_num_tx_queues(info->netdev, i);
1862 rtnl_unlock();
1863 goto destroy_ring;
1864 } else {
1865 goto out;
1866 }
1867 }
1868 }
1869
1870 again:
1871 err = xenbus_transaction_start(&xbt);
1872 if (err) {
1873 xenbus_dev_fatal(dev, err, "starting transaction");
1874 goto destroy_ring;
1875 }
1876
1877 if (num_queues == 1) {
1878 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
1879 if (err)
1880 goto abort_transaction_no_dev_fatal;
1881 } else {
1882 /* Write the number of queues */
1883 err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues",
1884 "%u", num_queues);
1885 if (err) {
1886 message = "writing multi-queue-num-queues";
1887 goto abort_transaction_no_dev_fatal;
1888 }
1889
1890 /* Write the keys for each queue */
1891 for (i = 0; i < num_queues; ++i) {
1892 queue = &info->queues[i];
1893 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
1894 if (err)
1895 goto abort_transaction_no_dev_fatal;
1896 }
1897 }
1898
1899 /* The remaining keys are not queue-specific */
1900 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
1901 1);
1902 if (err) {
1903 message = "writing request-rx-copy";
1904 goto abort_transaction;
1905 }
1906
1907 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
1908 if (err) {
1909 message = "writing feature-rx-notify";
1910 goto abort_transaction;
1911 }
1912
1913 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
1914 if (err) {
1915 message = "writing feature-sg";
1916 goto abort_transaction;
1917 }
1918
1919 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
1920 if (err) {
1921 message = "writing feature-gso-tcpv4";
1922 goto abort_transaction;
1923 }
1924
1925 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
1926 if (err) {
1927 message = "writing feature-gso-tcpv6";
1928 goto abort_transaction;
1929 }
1930
1931 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
1932 "1");
1933 if (err) {
1934 message = "writing feature-ipv6-csum-offload";
1935 goto abort_transaction;
1936 }
1937
1938 err = xenbus_transaction_end(xbt, 0);
1939 if (err) {
1940 if (err == -EAGAIN)
1941 goto again;
1942 xenbus_dev_fatal(dev, err, "completing transaction");
1943 goto destroy_ring;
1944 }
1945
1946 return 0;
1947
1948 abort_transaction:
1949 xenbus_dev_fatal(dev, err, "%s", message);
1950 abort_transaction_no_dev_fatal:
1951 xenbus_transaction_end(xbt, 1);
1952 destroy_ring:
1953 xennet_disconnect_backend(info);
1954 kfree(info->queues);
1955 info->queues = NULL;
1956 rtnl_lock();
1957 netif_set_real_num_tx_queues(info->netdev, 0);
1958 rtnl_unlock();
1959 out:
1960 return err;
1961 }
1962
1963 static int xennet_connect(struct net_device *dev)
1964 {
1965 struct netfront_info *np = netdev_priv(dev);
1966 unsigned int num_queues = 0;
1967 int err;
1968 unsigned int feature_rx_copy;
1969 unsigned int j = 0;
1970 struct netfront_queue *queue = NULL;
1971
1972 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1973 "feature-rx-copy", "%u", &feature_rx_copy);
1974 if (err != 1)
1975 feature_rx_copy = 0;
1976
1977 if (!feature_rx_copy) {
1978 dev_info(&dev->dev,
1979 "backend does not support copying receive path\n");
1980 return -ENODEV;
1981 }
1982
1983 err = talk_to_netback(np->xbdev, np);
1984 if (err)
1985 return err;
1986
1987 /* talk_to_netback() sets the correct number of queues */
1988 num_queues = dev->real_num_tx_queues;
1989
1990 rtnl_lock();
1991 netdev_update_features(dev);
1992 rtnl_unlock();
1993
1994 /*
1995 * All public and private state should now be sane. Get
1996 * ready to start sending and receiving packets and give the driver
1997 * domain a kick because we've probably just requeued some
1998 * packets.
1999 */
2000 netif_carrier_on(np->netdev);
2001 for (j = 0; j < num_queues; ++j) {
2002 queue = &np->queues[j];
2003
2004 notify_remote_via_irq(queue->tx_irq);
2005 if (queue->tx_irq != queue->rx_irq)
2006 notify_remote_via_irq(queue->rx_irq);
2007
2008 spin_lock_irq(&queue->tx_lock);
2009 xennet_tx_buf_gc(queue);
2010 spin_unlock_irq(&queue->tx_lock);
2011
2012 spin_lock_bh(&queue->rx_lock);
2013 xennet_alloc_rx_buffers(queue);
2014 spin_unlock_bh(&queue->rx_lock);
2015 }
2016
2017 return 0;
2018 }
2019
2020 /**
2021 * Callback received when the backend's state changes.
2022 */
2023 static void netback_changed(struct xenbus_device *dev,
2024 enum xenbus_state backend_state)
2025 {
2026 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2027 struct net_device *netdev = np->netdev;
2028
2029 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2030
2031 switch (backend_state) {
2032 case XenbusStateInitialising:
2033 case XenbusStateInitialised:
2034 case XenbusStateReconfiguring:
2035 case XenbusStateReconfigured:
2036 case XenbusStateUnknown:
2037 break;
2038
2039 case XenbusStateInitWait:
2040 if (dev->state != XenbusStateInitialising)
2041 break;
2042 if (xennet_connect(netdev) != 0)
2043 break;
2044 xenbus_switch_state(dev, XenbusStateConnected);
2045 break;
2046
2047 case XenbusStateConnected:
2048 netdev_notify_peers(netdev);
2049 break;
2050
2051 case XenbusStateClosed:
2052 if (dev->state == XenbusStateClosed)
2053 break;
2054 /* Missed the backend's CLOSING state -- fallthrough */
2055 case XenbusStateClosing:
2056 xenbus_frontend_closed(dev);
2057 break;
2058 }
2059 }
2060
2061 static const struct xennet_stat {
2062 char name[ETH_GSTRING_LEN];
2063 u16 offset;
2064 } xennet_stats[] = {
2065 {
2066 "rx_gso_checksum_fixup",
2067 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2068 },
2069 };
2070
2071 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2072 {
2073 switch (string_set) {
2074 case ETH_SS_STATS:
2075 return ARRAY_SIZE(xennet_stats);
2076 default:
2077 return -EINVAL;
2078 }
2079 }
2080
2081 static void xennet_get_ethtool_stats(struct net_device *dev,
2082 struct ethtool_stats *stats, u64 * data)
2083 {
2084 void *np = netdev_priv(dev);
2085 int i;
2086
2087 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2088 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2089 }
2090
2091 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2092 {
2093 int i;
2094
2095 switch (stringset) {
2096 case ETH_SS_STATS:
2097 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2098 memcpy(data + i * ETH_GSTRING_LEN,
2099 xennet_stats[i].name, ETH_GSTRING_LEN);
2100 break;
2101 }
2102 }
2103
2104 static const struct ethtool_ops xennet_ethtool_ops =
2105 {
2106 .get_link = ethtool_op_get_link,
2107
2108 .get_sset_count = xennet_get_sset_count,
2109 .get_ethtool_stats = xennet_get_ethtool_stats,
2110 .get_strings = xennet_get_strings,
2111 };
2112
2113 #ifdef CONFIG_SYSFS
2114 static ssize_t show_rxbuf(struct device *dev,
2115 struct device_attribute *attr, char *buf)
2116 {
2117 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2118 }
2119
2120 static ssize_t store_rxbuf(struct device *dev,
2121 struct device_attribute *attr,
2122 const char *buf, size_t len)
2123 {
2124 char *endp;
2125 unsigned long target;
2126
2127 if (!capable(CAP_NET_ADMIN))
2128 return -EPERM;
2129
2130 target = simple_strtoul(buf, &endp, 0);
2131 if (endp == buf)
2132 return -EBADMSG;
2133
2134 /* rxbuf_min and rxbuf_max are no longer configurable. */
2135
2136 return len;
2137 }
2138
2139 static struct device_attribute xennet_attrs[] = {
2140 __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
2141 __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
2142 __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL),
2143 };
2144
2145 static int xennet_sysfs_addif(struct net_device *netdev)
2146 {
2147 int i;
2148 int err;
2149
2150 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
2151 err = device_create_file(&netdev->dev,
2152 &xennet_attrs[i]);
2153 if (err)
2154 goto fail;
2155 }
2156 return 0;
2157
2158 fail:
2159 while (--i >= 0)
2160 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2161 return err;
2162 }
2163
2164 static void xennet_sysfs_delif(struct net_device *netdev)
2165 {
2166 int i;
2167
2168 for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
2169 device_remove_file(&netdev->dev, &xennet_attrs[i]);
2170 }
2171
2172 #endif /* CONFIG_SYSFS */
2173
2174 static int xennet_remove(struct xenbus_device *dev)
2175 {
2176 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2177 unsigned int num_queues = info->netdev->real_num_tx_queues;
2178 struct netfront_queue *queue = NULL;
2179 unsigned int i = 0;
2180
2181 dev_dbg(&dev->dev, "%s\n", dev->nodename);
2182
2183 xennet_disconnect_backend(info);
2184
2185 xennet_sysfs_delif(info->netdev);
2186
2187 unregister_netdev(info->netdev);
2188
2189 for (i = 0; i < num_queues; ++i) {
2190 queue = &info->queues[i];
2191 del_timer_sync(&queue->rx_refill_timer);
2192 }
2193
2194 if (num_queues) {
2195 kfree(info->queues);
2196 info->queues = NULL;
2197 }
2198
2199 free_percpu(info->stats);
2200
2201 free_netdev(info->netdev);
2202
2203 return 0;
2204 }
2205
2206 static const struct xenbus_device_id netfront_ids[] = {
2207 { "vif" },
2208 { "" }
2209 };
2210
2211 static struct xenbus_driver netfront_driver = {
2212 .ids = netfront_ids,
2213 .probe = netfront_probe,
2214 .remove = xennet_remove,
2215 .resume = netfront_resume,
2216 .otherend_changed = netback_changed,
2217 };
2218
2219 static int __init netif_init(void)
2220 {
2221 if (!xen_domain())
2222 return -ENODEV;
2223
2224 if (!xen_has_pv_nic_devices())
2225 return -ENODEV;
2226
2227 pr_info("Initialising Xen virtual ethernet driver\n");
2228
2229 /* Allow as many queues as there are CPUs, by default */
2230 xennet_max_queues = num_online_cpus();
2231
2232 return xenbus_register_frontend(&netfront_driver);
2233 }
2234 module_init(netif_init);
2235
2236
2237 static void __exit netif_exit(void)
2238 {
2239 xenbus_unregister_driver(&netfront_driver);
2240 }
2241 module_exit(netif_exit);
2242
2243 MODULE_DESCRIPTION("Xen virtual network device frontend");
2244 MODULE_LICENSE("GPL");
2245 MODULE_ALIAS("xen:vif");
2246 MODULE_ALIAS("xennet");
Linux kernel - Deliverables
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